An adaptive modulation and coding (AMC) technology is an adaptive technology by using which a modulation and coding scheme (MCS) is adaptively selected according to a radio channel state to improve a throughput rate of the wireless communications system on the premise that reliability of a wireless communications system is ensured.
A Long Term Evolution (LTE) system is used as an example. In the prior art, after receiving a reference signal sent by user equipment (UE), for example, a sounding reference signal (SRS) or a demodulation reference signal (DMRS), an evolved NodeB (eNB) measures an uplink signal to interference plus noise ratio (SINR) according to the reference signal, and performs smooth filtering on the SINR to obtain an uplink SINR smooth filtering value. When scheduling the UE, the evolved NodeB uses the uplink SINR smooth filtering value as a SINR predictor for performing actual data transmission by the UE after several transmission time intervals (TTI), corrects the SINR predictor by using a SINR adjustment amount so as to obtain a SINR measurement value, and acquires, according to the SINR measurement value and a correspondence between the uplink SINR and an uplink MCS, an output MCS that needs to be used.
However, due to discontinuity of UE services, data transmission for the UE is discontinuous in a time domain and frequently changes in a frequency domain. As a result, interference from a neighboring cell in the UE changes dramatically, and has is no time-domain correlation.
Therefore, a SINR in a data transmission subframe after several TTIs relative to a current TTI cannot be accurately predicted according to only a SINR measurement value at a historical moment. A problem that a system throughput rate decreases due to inaccurate MCS selection exists in the prior art.